U.S. patent application number 12/623727 was filed with the patent office on 2010-07-01 for electroplating method and electroplated product.
This patent application is currently assigned to BYD CO. LTD.. Invention is credited to Aihua Li, Zaichun Li, Bo Peng, Jipeng Sun.
Application Number | 20100167085 12/623727 |
Document ID | / |
Family ID | 42285328 |
Filed Date | 2010-07-01 |
United States Patent
Application |
20100167085 |
Kind Code |
A1 |
Sun; Jipeng ; et
al. |
July 1, 2010 |
Electroplating Method and Electroplated Product
Abstract
A method for electroplating a substrate having an aluminum alloy
surface comprises: applying a zinc layer onto the aluminum alloy
surface; electroplating a first copper layer onto the zinc layer
from an alkaline copper electroplating solution; electroplating a
second copper layer onto the first copper layer from an acid copper
electroplating solution; electroplating a Cu--Sn alloy layer onto
the second copper layer from a Cu--Sn electroplating solution; and
electroplating a chromium layer onto the Cu--Sn alloy layer from a
trivalent chromium solution. The alkaline copper electroplating
solution is substantially free of cyanide ion.
Inventors: |
Sun; Jipeng; (Shenzhen,
CN) ; Li; Aihua; (Shenzhen, CN) ; Li;
Zaichun; (Shenzhen, CN) ; Peng; Bo; (Shenzhen,
CN) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE
P.O. BOX 10395
CHICAGO
IL
60610
US
|
Assignee: |
BYD CO. LTD.
Shenzhen
CN
|
Family ID: |
42285328 |
Appl. No.: |
12/623727 |
Filed: |
November 23, 2009 |
Current U.S.
Class: |
428/650 ;
205/187 |
Current CPC
Class: |
C23C 28/021 20130101;
Y10T 428/12736 20150115; C25D 3/06 20130101; C23C 28/023 20130101;
C23C 28/025 20130101; C25D 3/38 20130101; C25D 3/58 20130101; C25D
5/12 20130101 |
Class at
Publication: |
428/650 ;
205/187 |
International
Class: |
B32B 15/01 20060101
B32B015/01; C23C 28/02 20060101 C23C028/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 26, 2008 |
CN |
200810241685.3 |
Claims
1. A method for electroplating a substrate having an aluminum alloy
surface comprising: applying a zinc layer onto the aluminum alloy
surface; electroplating a first copper layer onto the zinc layer
from an alkaline copper electroplating solution, wherein the
alkaline copper solution is substantially free of cyanide ion;
electroplating a second copper layer onto the first copper layer
from an acid copper electroplating solution; electroplating a
Cu--Sn alloy layer onto the second copper layer from a Cu--Sn
electroplating solution; and electroplating a chromium layer onto
the Cu--Sn alloy layer from a trivalent chromium solution.
2. The method of claim 1, wherein the zinc layer is formed by
placing the aluminum alloy in a zinc-containing solution; wherein
the zinc-containing solution comprises zinc oxide, sodium
hydroxide, potassium sodium tartrate, ferric chloride, sodium
nitrite, and water; and wherein the concentration of zinc oxide is
between about 20 and about 60 g/L, the concentration of sodium
hydroxide is between about 100 and about 130 g/L, the concentration
of potassium sodium tartrate is between about 40 and about 60 g/L,
the concentration of ferric chloride is between about 0.5 and about
2.5 g/L, and the concentration of sodium nitrite is between about
0.5 and about 4 g/L.
3. The method of claim 2, wherein the temperature of the
zinc-containing solution is between about 20 and about 28.degree.
C.; and the aluminum alloy is placed in the zinc-containing
solution for between about 40 seconds and about 2 minutes.
4. The method of claim 1, wherein the alkaline copper
electroplating solution comprises potassium pyrophosphate, copper
pyrophosphate, a stabilizing agent, a brightening agent, and water;
and wherein the concentration of potassium pyrophosphate is between
about 350 and about 420 g/L, the concentration of copper
pyrophosphate is between about 15 and about 25 g/L, the
concentration of the stabilizing agent is between about 65 and
about 85 ml/L, and the concentration of the brightening agent is
between about 15 and about 25 ml/L.
5. The method of claim 1, wherein the temperature of the alkaline
copper electroplating solution is between about 35 and about
60.degree. C.; the pH of the alkaline copper electroplating
solution is between about 9.2 and about 10.0; the electroplating
cathodic current density of the first copper layer is between about
0.5 and about 2.5 A/dm.sup.2; and the electroplating time for the
first copper layer is between about 5 minutes and about 20
minutes.
6. The method of claim 1, wherein the acid copper electroplating
solution comprises CuSO.sub.4, H.sub.2SO.sub.4, chloride ion, an
auxiliary agent, a smoothing agent, a brightening agent, and water;
and wherein the concentration of CuSO.sub.4 is between about 180
and about 250 g/L, the concentration of H.sub.2SO.sub.4 is between
about 50 and about 70 g/L, the concentration of chloride ion is
between about 40 and about 100 mg/L, the concentration of the
auxiliary agent is between about 8 and about 10 ml/L, the
concentration of the smoothing agent is between about 0.4 and about
0.6 ml/L, and the concentration of the brightening agent of about
0.4 and about 0.6 ml/L.
7. The method of claim 1, wherein the temperature of the acid
copper electroplating solution is between about 20 and about
30.degree. C., and the cathodic current density of the second
copper layer is between about 3 and about 5 A/dm.sup.2; the
electroplating time for the second copper layer is between about 15
minutes and about 40 minutes; and wherein an anode is made of
copper containing phosphorus in about 0.03 to 0.06% by weight.
8. The method of claim 1, wherein the electroplating of the second
copper layer further comprises steps of: stirring the copper
solution; and filtering the copper solution.
9. The method of claim 1, wherein the Cu--Sn electroplating
solution comprises potassium pyrophosphate, copper pyrophosphate,
stannous pyrophosphate, a complexing agent, a stabilizing agent,
and a brightening agent; wherein the concentration of potassium
pyrophosphate is between about 250 and about 350 g/L, the
concentration of copper pyrophosphate is between about 5 and about
12 g/L, the concentration of stannous pyrophosphate is between
about 15 and about 35 g/L, the concentration of the complexing
agent is between about 80 and about 120 ml/L, the concentration of
the stabilizing agent is between about 10 and about 30 ml/L, and
the concentration of the brightening agent is between about 10 and
about 20 ml/L.
10. The method of claim 1, wherein the temperature of the Cu--Sn
alloy electroplating solution is between about 15 and about
30.degree. C.; the pH of the Cu--Sn alloy electroplating solution
is between about 8.0 and about 8.8; the electroplating cathodic
current density of the Cu--Sn alloy layer is between about 0.5 and
about 1 A/dm.sup.2; and the electroplating time for the Cu--Sn
alloy layer is between about 5 minutes and about 15 minutes.
11. The method of claim 1, wherein the trivalent chromium
electroplating solution comprises an auxiliary agent, a stabilizing
agent, a wetting agent, a complexing agent and a trivalent chromium
compound; and wherein the auxiliary agent is between about 400 and
about 450 ml/L, the stabilizing agent is between about 55 and about
75 ml/L, the wetting agent is between about 2 and about 5 ml/L, the
complexing agent is between about 1 and about 3 ml/L, and trivalent
chromium is between about 20 and about 25 g/L.
12. The method of claim 1, wherein the temperature of the chromium
electroplating solution is between about 28 and about 35.degree.
C.; the pH of the chromium electroplating solution is between about
2.5 and about 3.0; the electroplating current density of the
chromium layer is between about 8 and about 30 A/dm.sup.2; and the
electroplating time for the chromium layer is between about 1
minutes and about 5 minutes.
13. The method of claim 1, wherein the electroplating of the
chromium layer further comprises steps of: stirring the chromium
solution; and filtering the chromium solution.
14. The method of claim 1, further comprising a step of treating
the aluminum alloy surface.
15. The method of claim 1, further comprising a step of washing
with water after at least one step of electroplating.
16. A method for electroplating a substrate having an aluminum
alloy surface comprising: applying a zinc layer onto the aluminum
alloy surface; electroplating a first copper layer onto the zinc
layer from an alkaline copper electroplating solution, wherein the
alkaline copper solution is substantially free of cyanide ion;
electroplating a second copper layer onto the first copper layer
from an acid copper electroplating solution; applying an activating
solution onto the second copper layer; electroplating a Cu--Sn
alloy layer onto the second copper layer from a Cu--Sn
electroplating solution; and electroplating a chromium layer onto
the Cu--Sn alloy layer from a trivalent chromium solution.
17. The method of claim 16, wherein the activating solution is an
acid.
18. The method of claim 17, wherein the acid is a H.sub.2SO.sub.4
solution.
19. The method of claim 16, further comprising a step of applying a
solution onto the Cu--Sn alloy layer.
20. An electroplated product comprising: a substrate having an
aluminum alloy surface; a zinc layer on the aluminum alloy surface;
a copper layer on the zinc layer, wherein the copper layer is
formed by electroplating from an alkaline copper electroplating
solution, and wherein the alkaline copper electroplating solution
is substantially free of cyanide ion; a Cu--Sn alloy layer on the
copper layer; and a chromium layer on Cu--Sn alloy layer; wherein
the electroplated layers are substantially free of nickel.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Chinese Patent
Application No. 200810241685.3, filed on Dec. 26, 2008, the
entirety of which is hereby incorporated by reference.
FIELD
[0002] The present disclosure relates to electroplating methods and
electroplated products made therefrom.
BACKGROUND
[0003] Because of their small density, good ductility and
toughness, easy molding processing, good electrical conductivity,
thermal conductivity, and other physical properties, aluminum
alloys have been widely used in modern aviation, aerospace,
electric power, electronics, petroleum, chemicals, building
materials, transportation, light industry, and national defense
industries. However, as a typical amphoteric metal, aluminum is
prone to corrosion in both acid and alkaline environments, which
limits the applications of aluminum and its alloys. In addition,
the surface hardness and wear resistance of aluminum alloy are
poor. Usually, surface treatment is used to overcome these
shortcomings and improve the product performance. The main methods
include: oxidation treatment, electroplating, plastic coating, and
spray painting.
[0004] Electroplating is the most widely used method. On the one
hand, it can retain or even strengthen the main physical
properties, such as electrical conductivity, thermal conductivity,
mechanical performance, etc. On another hand, it can avoid the
corrosion of acid and base environments, and expand the application
of aluminum alloys. Furthermore, electroplating can improve the
decorative effect on the surface of the aluminum alloys.
[0005] In general, two electroplating processes are used for
aluminum alloys. For example, the alloys are pre-treated, dipped
into a zinc-containing solution, coated with a nickel layer by a
chemical method, electroplated by a copper layer, electroplated by
a nickel layer, and electroplated by a chromium or gold layer. The
other process includes pre-treating, dipping into a zinc-containing
solution, electroplating a copper layer from a cyanide copper
solution, electroplating a copper layer from a pyrophosphate copper
solution, electroplating copper from an acid copper solution,
electroplating a nickel layer, and electroplating a chromium or
gold layer. These processes have shortcomings, such as poor
adhesion of the electroplated layers, high costs, difficult
treatments of waste water, and serious environmental pollutions.
The main disadvantages of nickel electroplating include that
exterior appearance may be affected by the nickel deposition, and
nickel would cause some people to have allergic reactions. The
current nickel-free electroplating processes include cyanide Cu--Sn
alloy electroplating, cyanide-free Sn--Co alloy electroplating,
cyanide-free Sn--Zn--Co alloy electroplating, cyanide-free Sn--Zn
alloy electroplating, and so on. The cyanide-free alloys do not
contain cyanide, but the color of the coatings is not bright. The
technique of cyanide Cu--Sn alloy electroplating is relatively
mature, but the high toxicity of cyanides limits its application,
and cyanide may cause serious environmental pollutions.
[0006] Therefore, a nickel-free and cyanide-free process is
desirable to electroplate aluminum alloys.
SUMMARY
[0007] In one aspect, a method for electroplating a substrate
having an aluminum alloy surface comprises: applying a zinc layer
onto the aluminum alloy surface; electroplating a first copper
layer onto the zinc layer from an alkaline copper electroplating
solution; electroplating a second copper layer onto the first
copper layer from an acid copper electroplating solution;
electroplating a Cu--Sn alloy layer onto the second copper layer
from a Cu--Sn electroplating solution; and electroplating a
chromium layer onto the Cu--Sn alloy layer from a trivalent
chromium solution. The alkaline copper electroplating solution is
substantially free of cyanide ion.
[0008] In another aspect, a method for electroplating a substrate
having an aluminum alloy surface comprises: applying a zinc layer
onto the aluminum alloy surface; electroplating a first copper
layer onto the zinc layer from an alkaline copper electroplating
solution; electroplating a second copper layer onto the first
copper layer from an acid copper electroplating solution; applying
an activating solution onto the second copper layer; electroplating
a Cu--Sn alloy layer onto the second copper layer from a Cu--Sn
electroplating solution; and electroplating a chromium layer onto
the Cu--Sn alloy layer from a trivalent chromium solution. The
alkaline copper electroplating solution is substantially free of
cyanide ion.
[0009] In yet another aspect, an electroplated product comprises a
substrate having an aluminum alloy surface; a zinc layer on the
aluminum alloy surface; a copper layer on the zinc layer, a Cu--Sn
alloy layer on the copper layer; and a chromium layer on Cu--Sn
alloy layer. The copper layer is formed by electroplating from an
alkaline copper electroplating solution, and the alkaline copper
solution is substantially free of cyanide ion. The electroplated
layers are substantially free of nickel.
DETAILED DESCRIPTION
[0010] It will be appreciated by those of ordinary skill in the art
that the embodiments disclosed herein can be embodied in other
specific forms without departing from the spirit or essential
character thereof. The presently disclosed embodiments are
therefore considered in all respects to be illustrative and not
restrictive.
[0011] A cyanide-free and nickel-free electroplating method for a
substrate having an aluminum alloy surface comprises: applying a
zinc layer onto the aluminum alloy surface; electroplating a first
copper layer onto the zinc layer from an alkaline copper
electroplating solution; electroplating a second copper layer onto
the first copper layer from an acid copper electroplating solution;
electroplating a Cu--Sn alloy layer onto the second copper layer
from a Cu--Sn electroplating solution; and electroplating a
chromium layer onto the Cu--Sn alloy layer from a trivalent
chromium solution. The alkaline copper electroplating solution is
substantially free of cyanide ions. The phrase "substantially free
of cyanide ions" is intended to refer to a solution that has no
more than a negligible amount of cyanide ions. In other words,
there are not enough cyanide ions to change the characteristics,
including the environmental impact, of the electroplating
solution.
[0012] Preferably, the zinc layer is formed by placing the
substrate into a zinc-containing solution. Preferably, the
zinc-containing solution is an aqueous solution, comprising zinc
oxide, sodium hydroxide, potassium sodium tartrate, ferric
chloride, and sodium nitrite. More preferably, the concentration of
zinc oxide is between about 20 and about 60 g/L. The concentration
of sodium hydroxide is between about 100 and about 130 g/L. The
concentration of potassium sodium tartrate is between about 40 and
about 60 g/L. The concentration of ferric chloride is between about
0.5 and about 2.5 g/L. The concentration of sodium nitrite is
between about 0.5 and about 4 g/L.
[0013] Preferably, the temperature of the zinc-containing solution
is between about 20 and about 28.degree. C. The substrate is placed
in the zinc-containing solution for between about 40 seconds and
about 2 minutes. The zinc-containing solution can be any suitable
solution containing zinc. It can be prepared in house, and can also
be bought in the market. For example, HAI-201 zinc-containing
solution (Fulite Chemical Co., Ltd. ShenZhen), Zincate CNF
zinc-containing solution (Tongdao Technologies Co., Ltd. ShenZhen),
and other commercially available products can be used in the
present disclosure.
[0014] In some embodiments, the non-conductive impurities on the
surface of the substrate material may affect the adhesion of the
electroplated layers. For example, cast or forged aluminum
substrates containing a high content of silicon are difficult to be
electroplated. To obtain a substrate with a smooth surface, the
silicon residual impurities should be removed. The removal of
residual impurities can be achieved by two times of treatment with
zinc-containing solutions. The substrate is placed in a first
zinc-containing solution and coated with a zinc layer. After the
zinc layer is removed, the substrate is coated with another layer
of zinc from a second zinc-containing solution. The first layer of
zinc can be removed with a solution of nitric acid and sodium
fluoride. Preferably, the weight percentage of nitric acid is about
50%. The weight percentage of sodium fluoride is about 2%. The
reaction can be carried out at room temperature for about 5 to
about 10 seconds. The first and second zinc-containing solution can
be the same solution. The conditions of the second treatment can
also be the same as the first treatment, except that the placing
time is about 10 to about 20 seconds.
[0015] After the treatment with the zinc-containing solution, a
beige uniform layer is formed on the surface. This layer may have a
strong adhesive force with both the substrate surface and the
subsequent electroplated layers.
[0016] The alkaline copper electroplating solution can be any
suitable basic copper solution. Preferably, the alkaline copper
electroplating solution comprises potassium pyrophosphate, copper
pyrophosphate, a stabilizing agent, a brightening agent, and water.
The concentration of potassium pyrophosphate is between about 350
and about 420 g/L. The concentration of copper pyrophosphate is
between about 15 and about 25 g/L. The concentration of the
stabilizing agent is between about 65 and about 85 ml/L. The
concentration of the brightening agent is between about 15 and
about 25 ml/L.
[0017] Preferably, the electroplating of the first copper layer is
conducted at a temperature between about 35 and about 60.degree.
C., at a cathodic current density between about 0.5 and about 2.5
A/dm.sup.2, and at a pH value between about 9.2 and about 10.0. The
electroplating time can be between about 5 minutes and about 20
minutes.
[0018] The alkaline copper electroplating solution can be prepared
in house or bought in the market. For example, the RK series
cyanide-free alkaline copper (NNK Co., Japan), SF-628 cyanide-free
alkaline copper series (Sanfu Co., Ltd. Guangzhou), CuMac Strike
XD7453 electroplating solution (MacDermid Co., US), and other
commercially available products can be used.
[0019] The acid copper electroplating is performed after the
cyanide-free alkaline copper electroplating. It can increase the
surface brightness of product and improve the visual effect. Any
suitable acid copper electroplating solution can be used.
Preferably, the acid copper electroplating solution is an aqueous
solution, comprising CuSO.sub.4, H.sub.2SO.sub.4, chloride ion, an
auxiliary agent, a smoothing agent, and a brightening agent.
[0020] More preferably, the concentration of CuSO.sub.4 is between
about 180 and about 250 g/L. The concentration of H.sub.2SO.sub.4
is between about 50 and about 70 g/L. The concentration of chloride
ion is between about 40 and about 100 mg/L. The concentration of
the auxiliary agent is between about 8 and about 10 ml/L. The
concentration of the smoothing agent is between about 0.4 and about
0.6 ml/L. The concentration of the brightening agent is between
about 0.4 and about 0.6 ml/L.
[0021] In one embodiment, the concentration of CuSO.sub.4 is about
220 g/L. The concentration of H.sub.2SO.sub.4 is about 50 g/L. The
concentration of chloride ion is about 100 mg/L. The concentration
of the auxiliary agent is about 8 ml/L. The concentration of the
smoothing agent is about 0.5 ml/L. The concentration of the
brightening agent is about 0.5 ml/L. The acid copper electroplating
solution can be prepared in house or be commercially available
products, such as Ultra acid copper electroplating solution
(Atotech Co., China). The Ultra solution (Atotech Co., China)
comprises CuSO.sub.4.5H.sub.2O of about 195 to 255 g/L,
H.sub.2SO.sub.4 of about 45 to 55 g/L, chlorine ion of about 40 to
100 mg/L, an auxiliary agent (ULTRA Make Up) of about 8 to 10 ml/L,
a smoothing agent (ULTRA A) of about 0.4 to 0.6 ml/L, a brightening
agent (ULTRA B) of about 0.4 to 0.6 ml/L.
[0022] Preferably, the electroplating of the second copper layer is
conducted at a temperature between about 20 and about 30.degree.
C., and at a cathodic current density between about 3 and about 5
A/dm.sup.2. Preferably, the electroplating time is between about 15
minutes and about 40 minutes. Preferably, the electroplating
solution is stirred and filtered during the electroplating process.
The electroplating solution can remain relatively uniform by
stirring. Filtering can remove impurities from the electroplating
solution.
[0023] Preferably, a copper ball containing phosphorus of about
0.03 to 0.06% by weight is used as an anode in the
electroplating.
[0024] Any suitable Cu--Sn alloy electroplating solution can be
used. Preferably, the Cu--Sn alloy electroplating solution is an
aqueous solution. Preferably, the solution comprises potassium
pyrophosphate of about 250 to 350 g/L, copper pyrophosphate of
about 5 to 12 g/L, stannous pyrophosphate of about 15 to 35 g/L, a
complexing agent of about 80 to 120 ml/L, a stabilizing agent of
about 10 to 30 ml/L, and a brightening agent of about 10 to 20
ml/L. Preferably, the conditions of the Cu--Sn alloy electroplating
comprise a temperature of about 15 to 30.degree. C., a cathodic
current density of about 0.5 to 1 A/dm.sup.2, a pH value of about
8.0 to about 8.8, and a electroplating time of about 5 minutes to
about 15 minutes. The Cu--Sn alloy electroplating solution can be
prepared in house or be commercially available products, such as
FSC white Cu--Sn (Mateys Co., Guangzhou), CS-138 white Cu--Sn
system (Dazhi Chemical Technology Co., Ltd. Guangzhou), and so
on.
[0025] Any suitable chromium electroplating solution can be used.
Preferably, the trivalent chromium electroplating solution is an
aqueous solution. Preferably, the solution comprises an auxiliary
agent of about 400 to 450 ml/L, a stabilizing agent of about 55 to
75 g/L, a wetting agent of about 2 to 5 ml/L, a complexing agent of
about 1 to 3 ml/L, and trivalent chromium of about 20 to 25 g/L. In
one embodiment, the concentration of the auxiliary agent is about
420 ml/L, the concentration of the stabilizing agent is about 65
g/L, the concentration of the wetting agent is about 3 ml/L, the
concentration of the complexing agent is about 2 ml/L, and the
concentration of the trivalent chromium is about 22 g/L. The
electroplating solutions can be prepared in house or be
commercially available products, such as TVC--trivalent chromium
electroplating solution (Shangma Technology Co., Ltd. Shenzhen).
The conditions of electroplating comprise a temperature of about 28
to 35.degree. C., a cathodic current density of about 8 to 30
A/dm.sup.2, a pH value of about 2.5 to about 3.0, and a
electroplating time of about 1 minute to about 5 minutes. The anode
can be a titanium alloy sheet or graphite. The electroplating
solution can remain relatively uniform by stirring. Filtering can
remove impurities from the electroplating solution. The
electroplating solution can be recycled by a filtering machine.
[0026] Preferably, the aluminum alloy surface is pretreated before
coating the zinc layer. The pretreatment can comprise the following
five steps.
[0027] 1. Mechanical polishing. The surface of the alloy is
polished by a high-speed polishing machine.
[0028] 2. Dewaxing and degreasing. The alloy is placed into a
degreasing and dewaxing fluid to remove waxes and greases. The
degreasing and dewaxing fluid can be Procleaner BR#1 dewaxing fluid
(YongXing Chemical Industry Co., Ltd.), or NO. 630 electrolysis
degreasing powder (International Chemical Industry Co., Ltd).
[0029] 3. Alkaline etching. The alloy is placed into an alkaline
solution for a period of time to remove oxides and silicon. The
alkaline solution can comprise sodium hydroxide of about 40 to 60
g/L, and ammonium bifluoride of about 90 to 120 g/L. The sodium
hydroxide can further remove greases, natural oxide films, and
slight scratches. The ammonium bifluoride can be used to remove the
silicon on the surface of alloy.
[0030] 4. Film removing. The aluminum alloy after treatment with
alkaline solutions has a non-uniform grey or black film on its
surface. The film can be removed by a film-removing solution. The
film-removing solution can comprise nitric acid with volume
fraction of about 30 to 40%, phosphoric acid with volume fraction
of about 50% to 70%, and ammonium bifluoride of about 5 to 30 g/L.
The temperature can be about 20 to 35.degree. C.
[0031] 5. Surface conditioning. Although the non-uniform black film
is removed by a film removing solution, an oxide layer is formed on
the surface of the alloy. A surface correcting solution can be used
to remove the oxide layer and neutralizing the surface. The
solution can comprise sodium carbonate of about 2 to 4 g/L.
Preferably, the treatment temperature is about 20 to 28.degree. C.
The treatment time is about 30 seconds to about 1 minute.
[0032] Preferably, the aluminum alloy surface receives an
activating treatment before and after the Cu--Sn alloy
electroplating to remove the oxide film on its surface. Any
suitable activating treatment can be used. Preferably, an
activating solution is used to active the electroplated layers. In
one embodiment, the activating solution is a hydrochloric acid or
sulfuric acid solution with a mass fraction of about 5%. The
activating time is between about 30 seconds to about 1 minute.
[0033] The surface of the substrate can be any type of aluminum
alloys, such as AC8A, TL177, ZL303, and KS282 aluminum alloys.
[0034] In some embodiments, electroplated products manufactured by
the above methods are disclosed. An electroplated product comprises
a substrate having an aluminum alloy surface; a zinc layer on the
aluminum alloy surface; a copper layer on the zinc layer, a Cu--Sn
alloy layer on the copper layer; and a chromium layer on Cu--Sn
alloy layer. The copper layer is formed by electroplating from an
alkaline copper electroplating solution, and the alkaline copper
solution is substantially free of cyanide ion. The electroplating
layers are substantially free of nickel. The phrase "substantially
free of nickel" is intended to refer to the layer that has no more
than a negligible amount of nickel.
[0035] The following embodiments are electroplating methods and
products according to the present disclosure.
EXAMPLE 1
[0036] The substrate material is AC8A aluminum alloy. It is treated
by the following steps.
[0037] (1) Mechanical Polishing.
[0038] The surface material is polished by a high speed polishing
machine. The surface roughness is reduced and the glossiness of the
surface is enhanced.
[0039] (2) Ultrasonic Dewaxing.
[0040] The Procleaner BR1 dewaxing fluid (YongXing Chemical
Industry Co., Ltd.) is used. The initial concentration is about 30
ml/L. The temperature is about 65.degree. C. The treatment time is
about 5 minutes.
[0041] (3) Cathodic Electrolytic Degreasing.
[0042] The NO. 630 electrolysis degreasing powder (International
Chemical Industry Co., Ltd) is used. The initial amount is about 50
g/L. The temperature is about 65.degree. C. The current density is
about 5 A/dm.sup.3. The treatment time is about 1 minute.
[0043] (4) Alkaline Etching.
[0044] The alkaline solution includes sodium hydroxide with an
initial concentration of about 40 g/L, and ammonium bifluoride with
an initial concentration of about 90 g/L. The temperature is about
25.degree. C. The treatment time is about 1 minute.
[0045] (5) Film Removing.
[0046] The film-removing solution includes nitric acid with a
volume fraction of about 30%, phosphoric acid with a volume
fraction of about 70%, and about 10 g/L ammonium hydrogen fluoride.
The temperature is about 25.degree. C. The treatment time is about
20 seconds.
[0047] (6) Surface Conditioning.
[0048] The surface correcting solution contains sodium carbonate
with a concentration of about 2 g/L. The temperature is room
temperature, and the treatment time is about 1 minute.
[0049] (7) Zinc Coating.
[0050] The zinc-containing solution comprises zinc oxide with a
concentration of about 20 g/L, sodium hydroxide with a
concentration of about 100 g/L, potassium sodium tartrate with a
concentration of about 40 g/L, ferric chloride with a concentration
of about 0.5 g/L, and sodium nitrite with a concentration of about
0.5 g/L. The electroplating temperature is about 23.degree. C. and
the electroplating time is about 60 seconds.
[0051] (8) Cyanide-Free Alkaline Copper Electroplating.
[0052] The CuMac Strike XD7453 electroplating solution (MacDermid
Co., US) is used, which comprises CuMac Strike Make up solution
with a concentration of about 125 ml/L, Equivalent copper meta with
a concentration of about 4.5 g/L, CuMac Strike Stabilizer with a
concentration of about 60 ml/L, and CuMac Strike Buffer with a
concentration of about 40 ml/L. The temperature is about 60.degree.
C. The cathodic current density is about 1 A/dm.sup.2. The pH value
is about 9.5 and the electroplating time is about 20 minutes.
[0053] (9) Acid Copper Electroplating.
[0054] The Ultra Acid Copper electroplating solution (Atotech Co.,
China) is used, which comprises CuSO.sub.4.5H.sub.2O with a
concentration of about 195 g/L, H.sub.2SO.sub.4 with a
concentration of about 45 g/L, chlorine ion with a concentration of
about 45 mg/L, an auxiliary agent ULTRA Make Up with a
concentration of about 8 ml/L, a smoothing agent ULTRA A with a
concentration of about 0.4 ml/L, a brightening agent ULTRA B with a
concentration of about 0.4 ml/L. The conditions of electroplating
comprise a temperature of about 25.degree. C., and a cathodic
current density of about 4 A/dm.sup.2. The anode is a copper ball
containing phosphorus at about 0.05% by weight. The electroplating
time is about 30 minutes. The solution is stirred and filtered
during the electroplating process.
[0055] (10) Activating Treatment.
[0056] The activating solution is a H.sub.2SO.sub.4 solution with a
mass fraction of about 5%. The activating time is about 30 seconds
and the activating temperature is room temperature.
[0057] (11) Cu--Sn Alloy Electroplating.
[0058] The FSC White Cu--Sn (Mateys Co., Guangzhou) is used, which
comprises potassium pyrophosphate with a concentration of about 250
g/L, copper pyrophosphate with a concentration of about 5 g/L,
stannous pyrophosphate with a concentration of about 15 g/L, a
complexing agent FCS-A with a concentration of about 80 ml/L, a
stabilizing agent FCS-B with a concentration of about 10 ml/L and a
brightening agent FCS-C with a concentration of about 10 ml/L. The
temperature is about 20.degree. C., the cathodic current density is
about 0.5 A/dm.sup.2, the pH value is about.5, and the
electroplating time is about 5 minutes.
[0059] (12) Activating Treatment.
[0060] The activating solution is a HCl solution with a mass
fraction of about 5%, the activating time is about 30 seconds and
the activating temperature is room temperature.
[0061] (13) Trivalent Chromium Electroplating.
[0062] The TVC- trivalent chromium electroplating solution (Shangma
Technology Co., Ltd. Shenzhen) is used, which comprises an
auxiliary agent TVC-BC with a concentration of about 400 ml/L, a
stabilizing agent TVC-CAT with a concentration of about 55 ml/L, a
wetting agent TVC-MS with a concentration of about 2 ml/L, a
complexing agent TVC-EXT with a concentration of about 1 ml/L, and
trivalent chromium with a concentration of about 20 g/L. The
temperature is about 25.degree. C., the cathodic current density is
about 14 A/dm.sup.2, the pH value is about 2.8, the electroplating
time is about 1 minute. The solution is stirred mechanically and
filtered continuously.
[0063] The alloy is washed with water after each step.
[0064] The electroplated product is labeled as A1.
EXAMPLE 2
[0065] The substrate material is YL177 aluminum alloy. It is
treated by the following steps.
[0066] The steps (1)-(6) are the same as described in EXAMPLE
1.
[0067] (7) Zinc Coating.
[0068] The zinc-containing solution comprises zinc oxide with a
concentration of about 40 g/L, sodium hydroxide with a
concentration of about 125 g/L, potassium sodium tartrate with a
concentration of about 50 g/L, ferric chloride with a concentration
of about 1.5 g/L, and sodium nitrite with a concentration of about
2 g/L. The temperature is about 23.degree. C. and the time is about
45 seconds.
[0069] (8) Cyanide-Free Alkaline Copper Electroplating
[0070] The CuMac Strike XD7453 electroplating solution (MacDermid
Co., US) is used, which comprises CuMac Strike Make up solution
with a concentration of about 150 ml/L, Equivalent copper metal
with a concentration of about 5.5 g/L, CuMac Strike Stabilizer with
a concentration of about 60 ml/L, and CuMac Strike Buffer with a
concentration of about 50 ml/L. The temperature is about 60.degree.
C., the cathodic current density is about 1 A/dm.sup.2, the pH
value is about 9.5 and the electroplating time is 2 minutes.
[0071] (9) Acid Copper Electroplating.
[0072] The Ultra acid copper electroplating solution (Atotech Co.,
China) is used, which comprises CuSO.sub.4.5H.sub.2O with a
concentration of about 220 g/L, H.sub.2SO.sub.4 with a
concentration of about 50 g/L, chlorine ion with a concentration of
about 100 mg/L, ULTRA Make Up with a concentration of about 8 ml/L,
a smoothing agent ULTRA A with a concentration of about 0.5 ml/L, a
brightening agent ULTRA B with a concentration of about 0.5 ml/L.
The conditions of acid copper electroplating comprise a temperature
of about 25.degree. C., and a cathodic current density of about 3.5
A/dm.sup.2. The anode is a copper ball containing phosphorus at
about 0.05% by weight. The electroplating time is about 25 minutes.
The solution is stirred and filtered continuously.
[0073] (10) Activating Treatment.
[0074] The activating solution is a H.sub.2SO.sub.4 solution with a
mass fraction of about 5%. The activating time is about 30 seconds,
and the activating temperature is room temperature.
[0075] (11) Cu--Sn Alloy Electroplating.
[0076] The FSC white Cu--Sn electroplating solution (Mateys Co.,
GuangZhou) is used, which comprises potassium pyrophosphate with a
concentration of about 320 g/L, copper pyrophosphate with a
concentration of about 10 g/L, stannous pyrophosphate with a
concentration of about 25 g/L, a complexing agent FCS-A with a
concentration of about 100 ml/L, a stabilizing agent FCS-B with a
concentration of about 20 ml/L, and a brightening agent FCS-C with
a concentration of about 15 ml/L. The temperature is about
25.degree. C., the cathodic current density is about 0.8
A/dm.sup.2, the pH value is about 8.5, and the electroplating time
is about 10 minutes.
[0077] (12) Activating Treatment.
[0078] The activating solution is a HCl solution with a mass
fraction of about 5%. The activating time is about 30 seconds, and
the activating temperature is room temperature.
[0079] (13) Trivalent Chromium Electroplating
[0080] The TVC--trivalent chromium electroplating solution (Shangma
Technology Co., Ltd. Shenzhen) is used, which comprises TVC-BC with
a concentration of about 420 ml/L, a stabilizing agent TVC-CAT with
a concentration of about 65 ml/L, a wetting agent TVC-MS with a
concentration of about 3 ml/L, a complexing agent TVC-EXT with a
concentration of about 2 ml/L, and trivalent chromium with a
concentration of about 22 g/L. The temperature is about 32.degree.
C., the cathodic current density is about 14 A/dm.sup.2, and the pH
value is about 2.8. The electroplating time is about 2 minute. The
solution is stirred mechanically and filtered continuously.
[0081] The alloy is washed with water after each step.
[0082] The electroplated product is labeled as A2.
EXAMPLE 3
[0083] The substrate material is ZL102 aluminum alloy. It is
treated with the following steps.
[0084] The steps (1)-(6) are the same as in EXAMPLE 1.
[0085] (7) Zinc Coating.
[0086] The zinc-containing solution comprises zinc oxide with a
concentration of about 60 g/L, sodium hydroxide with a
concentration of about 130 g/L, potassium sodium tartrate with a
concentration of about 60 g/L, ferric chloride with a concentration
of about 1.5 g/L, and sodium nitrite with a concentration of about
3.5 g/L. The temperature is about 20.degree. C. and the time is
about 2 minutes.
[0087] (8) Cyanide-Free Alkaline Copper Electroplating.
[0088] The CuMac Strike XD7453 electroplating solution (MacDermid
Co., US) is used, which comprises CuMac Strike Make Up solution
with a concentration of about 200 ml/L, Equivalent Copper Metal
with a concentration of about 7.5 g/L, CuMac Strike Stabilizer with
a concentration of about 70 ml/L, and CuMac Strike Buffer with a
concentration of about 80 ml/L. The temperature is about 35.degree.
C., the cathodic current density is about 1 A/dm.sup.2, the pH
value is about 9.5, and the electroplating time is about 5
minutes.
[0089] (9) Acid Copper Electroplating.
[0090] The Ultra acid copper electroplating solution (Atotech Co.,
China) is used, which comprises CuSO.sub.4.5H.sub.2O with a
concentration of about 225 g/L, H.sub.2SO.sub.4 with a
concentration of about 55 g/L, chlorine ion with a concentration of
about 100 mg/L, ULTRA Make Up with a concentration of about 10
ml/L, a smoothing agent ULTRA A with a concentration of about 0.6
ml/L, a brightening agent ULTRA B with a concentration of about 0.6
ml/L. The conditions of acid copper electroplating comprise a
temperature of about 25.degree. C., a cathodic current density of
about 4 A/dm.sup.2. The anode is a copper ball containing
phosphorus of about 0.05% by weight. The electroplating time of
about 25 minutes. The solution is stirred mechanically and filtered
continuously.
[0091] (10) Activating Treatment.
[0092] The activating solution is H.sub.2SO.sub.4 with a mass
fraction of about 5%. The activating time is about 30 seconds, and
the activating temperature is room temperature.
[0093] (11) Cu--Sn Alloy Electroplating.
[0094] The FSC white Cu--Sn (Mateys Co., GuangZhou) is used, which
comprises potassium pyrophosphate with a concentration of about 350
g/L, copper pyrophosphate with a concentration of about 12 g/L,
stannous pyrophosphate with a concentration of about 35 g/L, a
complexing agent FCS-A with a concentration of about 120 ml/L, a
stabilizing agent FCS-B with a concentration of about 30 ml/L, and
a brightening agent FCS-C with a concentration of about 20 ml/L.
The temperature is about 32.degree. C., the cathodic current
density is about 1 A/dm.sup.2, the pH value is about 8.5, and the
electroplating time is about 10 minutes.
[0095] (12) Activating Treatment.
[0096] The activating solution is a HCl solution with a mass
fraction of about 5%. The activating time is about 30 seconds, and
the activating temperature is room temperature.
[0097] (13) Trivalent Chromium Electroplating.
[0098] The TVC--trivalent chromium electroplating solution (Shangma
Technology Co., Ltd. Shenzhen) is used, which comprises TVC-BC with
a concentration of about 450 ml/L, a stabilizing agent TVC-CAT with
a concentration of about 75 ml/L, a wetting agent TVC-MS with a
concentration of about 5 ml/L, a complexing agent TVC-EXT with a
concentration of about 3 ml/L, and trivalent chromium with a
concentration of about 25 g/L. The temperature is about 32.degree.
C., the cathodic current density is about 14 A/dm.sup.2, the pH
value is about 2.8, the electroplating time is about 5 minutes. The
solution is stirred mechanically and filtered continuously.
[0099] The alloy is washed with water after each step of
treatment.
[0100] The electroplated product is labeled as A3.
EXAMPLE 4
[0101] The substrate material is AC8A aluminum alloy. It is treated
with the following steps.
[0102] The steps (1)-(6) are the same as in EXAMPLE 1.
[0103] (7) Zinc Coating.
[0104] The zinc-containing solution comprises zinc oxide with a
concentration of about 40 g/L, sodium hydroxide with a
concentration of about 125 g/L, potassium sodium tartrate with a
concentration of about 50 g/L, ferric chloride with a concentration
of about 1.5 g/L, and sodium nitrite with a concentration of about
2 g/L. The temperature is about 23.degree. C. and the time is about
60 seconds.
[0105] (8) Cyanide-Free Alkaline Copper Electroplating.
[0106] The CuMac Strike XD7453 electroplating solution (MacDermid
Co., US) is used, which comprises CuMac Strike Make up solution
with a concentration of about 150 ml/L, Equivalent Copper Metal
with a concentration of about 5.5 g/L, CuMac Strike Stabilizer with
a concentration of about 65 ml/L, and CuMac Strike Buffer with a
concentration of about 50 ml/L. The temperature is about 50.degree.
C., the cathodic current density is about 1 A/dm.sup.2, the pH
value is about 9.5, and the electroplating time is about 5
minutes.
[0107] (9) Acid Copper Electroplating.
[0108] The Ultra acid copper electroplating solution (Atotech Co.,
China) is used, which comprises CuSO.sub.4.5H.sub.2O with a
concentration of about 220 g/L, H.sub.2SO.sub.4 with a
concentration of 50 g/L, chlorine ion with a concentration of about
100 mg/L, ULTRA Make Up with a concentration of about 8 ml/L, a
smoothing agent ULTRA A with a concentration of about 0.4 ml/L, a
brightening agent ULTRA B with a concentration of about 0.5 ml/L.
The conditions of acid copper electroplating comprise a temperature
of about 25.degree. C., and a cathodic current density of about 4
A/dm.sup.2. The anode is a copper ball containing phosphorus of
about 0.05% by weight. The electroplating time is about 30 minutes.
The solution is stirred and filtered continuously during the
electroplating process.
[0109] (10) Activating Treatment.
[0110] The activating solution is a H.sub.2SO.sub.4 solution with a
mass fraction of about 5%. The activating time is about 1 minute,
and the activating temperature is room temperature.
[0111] (11) Cu--Sn Alloy Electroplating.
[0112] The FSC white Cu--Sn electroplating solution (Mateys Co.,
GuangZhou) is used, which comprises potassium pyrophosphate with a
concentration of about 320 g/L, copper pyrophosphate with a
concentration of about 10 g/L, stannous pyrophosphate with a
concentration of about 20 g/L, a complexing agent FCS-A with a
concentration of about 100 ml/L, a stabilizing agent FCS-B with a
concentration of about 20 ml/L, and a brightening agent FCS-C with
a concentration of about 15 ml/L. The temperature is about
25.degree. C., the cathodic current density is about 0.8
A/dm.sup.2, the pH value is about 8.5, and the electroplating time
is about 10 minutes.
[0113] (12) Activating Treatment.
[0114] The activating solution is a HCl solution with a mass
fraction of about 5%. The activating time is about 30 seconds and
the activating temperature is room temperature.
[0115] (13) Trivalent Chromium Electroplating.
[0116] The TVC--trivalent chromium electroplating solution (Shangma
Technology Co., Ltd. Shenzhen) is used, which comprises TVC-BC with
a concentration of about 425 ml/L, a stabilizing agent TVC-CAT with
a concentration of about 65 ml/L, a wetting agent TVC-MS with a
concentration of about 3 ml/L, a complexing agent TVC-EXT with a
concentration of about 2 ml/L, and trivalent chromium with a
concentration of about 22 g/L. The temperature is about 35.degree.
C., the cathodic current density is about 30 A/dm.sup.2, the pH
value is about 2.8, and the electroplating time is about 2 minute.
The solution is stirred mechanically and filtered continuously
during the electroplating.
[0117] The alloy is washed with water after each step.
[0118] The electroplated product is labeled as A4.
CONTROL 1
[0119] The substrate material is YL177 aluminum alloy (the same as
EXAMPLE 2). It is treated with the following steps.
[0120] The steps (1)-(6) are the same as described in EXAMPLE
1.
[0121] (7) Zinc Coating.
[0122] The zinc-containing solution comprises zinc oxide with a
concentration of about 40 g/L, sodium hydroxide with a
concentration of about 125 g/L, potassium sodium tartrate with a
concentration of about 50 g/L, ferric chloride with a concentration
of about 1.5 g/L, and sodium nitrite with a concentration of about
2 g/L. The temperature is about 23.degree. C. and the time is about
45 seconds.
[0123] (8) Nickel Plating.
[0124] The JS-998 bright electro-less nickel (Ensoo (Tai Zhou)
Chemicals Co., Ltd.) is used. The electroplating solution comprises
JS-998A with a concentration of about 60 ml/L, and JS-998B with a
concentration of about 150 ml/L. The temperature is about
88.degree. C., the pH value is about 4.7, and the electroplating
time is about 25 minutes.
[0125] (9) Acid Copper Electroplating.
[0126] The Ultra acid copper electroplating solution (Atotech Co.,
China) is used, which comprises CuSO.sub.4.5H.sub.2O with a
concentration of about 220 g/L, H.sub.2SO.sub.4 with a
concentration of about 50 g/L, chlorine ion with a concentration of
about 100 mg/L, ULTRA Make Up with a concentration of about 8 ml/L,
a smoothing agent ULTRA A with a concentration of about 0.5 ml/L, a
brightening agent ULTRA B with a concentration of about 0.5 ml/L.
The conditions of acid copper electroplating comprise a temperature
of about 25.degree. C., and a cathodic current density of about 4
A/dm.sup.2. The anode is a copper ball containing phosphorus of
about 0.05% by weight. The electroplating time is about 25 minutes.
The solution is stirred and filtered continuously.
[0127] (10) Activating Treatment.
[0128] The activating solution is a H.sub.2SO.sub.4 solution with a
mass fraction of about 5%. The activating time is about 30 seconds,
and the activating temperature is room temperature.
[0129] (11) Semi-Bright Nickel Plating.
[0130] The SM-600 sulfurate-free semi-bright nickel electroplating
solution (International Chemical Industry Co., Ltd) is used, which
comprises nickel sulfate with a concentration of about 250 g/L,
nickel chloride with a concentration of about 50 g/L, boric acid
with a concentration of about 45 g/L, an auxiliary agent SM-A 600A
with a concentration of about 10 ml/L, a stabilizing agent SM-A
600C with a concentration of about 0.4 ml/L, a brightening agent
SM-A 600B with concentration of about 0.6 ml/L, and a Ni-905
wetting agent with a concentration of about 3 ml/L. The temperature
is about 55.degree. C., the cathodic current density is about 2
A/dm.sup.2, the pH value is about 3.8, and the electroplating time
is about 5 minutes.
[0131] (12) Bright Nickel Plating.
[0132] The NIKEL 88 BRIGHTNISM bright nickel 88 electroplating
solution (Atotech Co., China) is used, which comprises nickel
sulfate with a concentration of about 250 g/L, nickel chloride with
a concentration of about 55 g/L, boric acid with a concentration of
about 40 g/L, a Ni SA-1 auxiliary agent with a concentration of
about 4 ml/L, an A-5 (4.times.) softening agent with a
concentration of about 10 ml/L, a Ni 88 main brightening agent with
a concentration of about 0.75 ml/L, a Ni Y-19 wetting agent with a
concentration of about 1.5 ml/L. The temperature is 55.degree. C.,
the cathodic current density is about 4 A/dm.sup.2, the pH value is
about 4.3, and the electroplating time is about 10 minutes.
[0133] (13) Activating Treatment.
[0134] The activating solution is a HCl solution with a mass
fraction of about 5%. The activating time is about 30 seconds, and
the activating temperature is room temperature.
[0135] (14) Trivalent Chromium Electroplating.
[0136] The TVC--trivalent chromium electroplating solution (Shangma
Technology Co., Ltd. Shenzhen) is used, which comprises TVC-BC with
a concentration of about 420 ml/L, a stabilizing agent TVC-CAT with
a concentration of about 65 ml/L, a wetting agent TVC-MS with a
concentration of about 3 ml/L, a complexing agent TVC-EXT with a
concentration of about 2 ml/L, and trivalent chromium with a
concentration of about 22 g/L. The temperature is about 32.degree.
C., the cathodic current density is about 14 A/dm.sup.2, the pH
value is about 2.8, the electroplating time is about 2 minute. The
solution is stirred mechanically and filtered continuously.
[0137] The alloy is washed with water after each step.
[0138] The electroplated product is labeled as AC1.
TESTING
[0139] 1. Cross-Cut Testing
[0140] The testing standard ISO 2409 is used.
[0141] Using a cutting device and cutting guide, cuts are made into
the coating layer to a depth sufficient to expose the substrate.
The cuts form several squares with similar sizes. The width of the
coating between each cutting line is about 1 millimeter. For the
products with a small surface, cutting lines form crosses. The
surfaces of the samples are brushed by 5 times along the direction
of the cutting lines. Then a 3M tape is applied onto the surfaces.
The tape is adhered closely onto the surface of the coated
products. Within about 5 minutes, the adhesive tape is lifted and
removed in about 0.5 to 1 second from a direction of about
60.degree. with the surfaces of the products.
[0142] The qualities of the products are ranked on a scale of 0-4,
with 0-1 being passed. For the products with crossing cuttings,
they are acceptable if the coating is not peeled off or the cutting
lines are not enlarged. Scale 0 is assigned to the products with
smooth cutting edges and no coating being peeled off. Scale 1 is
assigned to the products where the peeled coating area is less than
5%. Scale 2 is assigned to the products where the peeled coating
area is between 5% and 15%. Scale 3 is assigned to the products
where the peeled coating area is between 15% and 35%. Scale 4 is
assigned to the products where the peeled coating area is between
35% and 65%.
[0143] 2. Vibratory Wear Testing
[0144] The abrasives are placed into a tank of a vibratory wear
machine. The amount of abrasives are about 15 L, including 3 parts
of yellow cone particles (Rosler wear particles RKF 10K) and 1 part
of green pyramid particles (Rosler wear particles RKFK 15P). The
abrasives are immersed in 2 L of water and wore for 4 hours in the
machine.
[0145] The abrasives remained wet before and in the testing
process. Therefore, before testing, 1 L of water is added into the
tank. The mixture of about 0.1 to 0.2 liters of Rosler cleaning
agent FC120 and water (with a ratio of 0.1 L of cleaning agent to 5
liters water) are added into the tank before the test. Then the
product is placed into the tank and tested. During the test, about
0.5 liters water is added in every half hour.
[0146] The products are acceptable if corners are not worn out
after 1 hour of testing, and the other parts are not worn out after
2 hour of testing.
[0147] 3. Salt Mist Endurance Testing
[0148] Salt mist (NaCl with a mass fraction of about 5%, and pH of
about 6.5 to 7.2) is sprayed on the products at 35.degree. C. for 2
hours. Then the products are placed in a chamber at 40.degree. C.
with a humidity of 80% for 168 hours.
[0149] The products are acceptable if 2 hours after testing, the
products do not show any visible corrosion, oxidation, or
deformation without washing.
[0150] 4. Thermal Shock Testing
[0151] The products are placed in a chamber at -40.degree. C. for 2
hours, and then they are transferred to another chamber at
85.degree. C. for 2 hours. The transferring time is less than 3
minutes. These processes are repeated for 5 times and lasted for
about 20 hours. The products are placed at room temperature for 2
hours after the test.
[0152] The products are acceptable if the mechanical properties of
the products are normal, and the mechanical components of the
products are not damaged.
[0153] The test results are shown in table 1.
TABLE-US-00001 TABLE 1 Cross- Vibratory Thermal Salt Mist Appear-
Cut Wear Shock Endurance ance of Testing Testing Testing Testing
Surfaces A1 Scale 0 Not wear out No bubbles No corrosion Smooth
after 2 hours after 5 times after 168 hours A2 Scale 0 Not wear out
No bubbles No corrosion Smooth after 2 hours after 5 times after
168 hours A3 Scale 0 Not wear out No bubbles No corrosion Smooth
after 2 hours after 5 times after 168 hours A4 Scale 0 Not wear out
No bubbles No corrosion Smooth after 2 hours after 5 times after
168 hours AC1 Scale 1 Not wear out Bubbles No corrosion Pits after
2 hours after 5 times after 168 hours
[0154] According to the test results, the electroplated product A2
has a coating with better qualities.
[0155] Many modifications and other embodiments of the present
disclosure will come to mind to one skilled in the art to which the
present disclosure pertains having the benefit of the teachings
presented in the foregoing description. It will be apparent to
those skilled in the art that variations and modifications of the
present disclosure can be made without departing from the scope or
spirit of the present disclosure. Therefore, it is to be understood
that the invention is not to be limited to the specific embodiments
disclosed and that modifications and other embodiments are intended
to be included within the scope of the appended claims. Although
specific terms are employed herein, they are used in a generic and
descriptive sense only and not for purposes of limitation.
* * * * *